1. Field of the Invention
The present invention relates to a method of forming an oxide layer and a method of forming an oxynitride layer. More particularly, the present invention relates to a method of forming a very thin oxide layer having excellent uniformity and characteristics on a substrate using a batch type apparatus, and a method of forming a very thin oxynitride layer by nitrifying the oxide layer on the substrate.
2. Description of the Related Art
As information processing systems such as computers have been widely utilized, semiconductor devices also have been rapidly developed. Thus, semiconductor manufacturing technologies have improved to produce semiconductor devices having large storage capacity, high response speed, high integration degree, good reliability, etc.
As the design rule of the semiconductor device decreases, the sizes of patterns of the semiconductor device also greatly decrease. For example, in a metal oxide semiconductor (MOS) transistor, a gate insulation layer between a gate electrode and a substrate has exceedingly reduced thickness and width. Various semiconductor devices such as dynamic random access memory (DRAM) devices, static random access memory (SRAM) devices, or flash memory devices demand an oxide layer having a thickness of several tens of angstroms (Å) as a gate insulation layer. In particular, a logic device for driving a memory circuit requires an extremely thin oxide layer of about 10 Å as the gate insulation layer. Therefore, it is required to form a very thin oxide layer on a substrate as the gate insulation layer.
When the gate insulation layer of the semiconductor device is very thin, impurities doped in the gate electrode may diffuse into the substrate through the thin gate insulation layer. Hence, before forming the gate electrode on the gate insulation layer, an oxynitride layer may be formed on the gate insulation layer to prevent the impurities in the gate electrode from diffusing into the substrate.
In a conventional semiconductor manufacturing method, the very thin oxide or oxynitride layer is formed using a single type apparatus such as a rapid thermal processing (RTP) apparatus since the very thin oxide or oxynitride layer may not have a precisely controlled thickness and may have poor uniformity and quality when a batch type apparatus is used. Additionally, a native oxide layer may be formed on the very thin oxide layer when the oxide layer is formed using the batch type apparatus. On the other hand, the very thin oxide or oxynitride layer formed in the single type apparatus may have poor electrical characteristics because thermal damage may occur to the very thin oxide or oxynitride layer.